MIAMI -- Before Casey McGehee signed in December, it was unclear who would play third base for the Marlins this season. But the organization has little doubt whom it expects to secure the hot corner for years to come.

Colin Moran, the sixth overall pick in the 2013 First-Year Player Draft, is considered the third baseman of the future. The question is when?

Moran has yet to play a full season of professional baseball, and the team is in no rush to speed up his development. What's attractive to the Marlins is Moran's upside.

In 2013, the left-handed-hitting third baseman helped lead the University of North Carolina to the College World Series. After signing with Miami, he got a taste of professional ball, appearing in 42 games with Class A Greensboro. Moran played an additional 22 games in the Arizona Fall League, and chances are he will open this year with Class A Advanced Jupiter.

Moran's realistic arrival date may very well be Opening Day 2015, unless he's a September callup this year. Whenever that day is, he will reach the big leagues highly touted.

According to MLB.com, Moran ranks fifth on the Top 10 list of third-base prospects. He joins some elite company. Miguel Sano of the Twins is rated No. 1 overall. Kris Bryant (Cubs), Nick Castellanos (Tigers), Maikel Franco (Phillies) and Moran, respectively, round out the top five.

A 6-foot-4, 190-pounder, Moran was regarded as one of the top collegiate hitters in the country at the time he was drafted. He is considered a pure hitter with power potential. The Marlins envision him as a long-term answer at third base, a position that has been in transition since Miguel Cabrera was traded to Detroit in 2007.

The past six years, the Marlins have tried a number of third-base options. Jorge Cantu, Emilio Bonifacio, Wes Helms, Alfredo Amezaga, Greg Dobbs, Hanley Ramirez and Placido Polanco have each been given chances, either as regulars or matchup options. Along with Polanco, Ed Lucas saw significant time at third last year.

Miami anticipates McGehee, who signed for $1.1 million as a free agent, will be the answer this year. One reason the Marlins didn't trade a pitching prospect for a long-term third-base candidate is because of their commitment to Moran.

"Moran definitely had an influence in our decision-making process," president of baseball operations Michael Hill said after McGehee signed last month. "Obviously, we invested a lot in him with the sixth pick overall. We wanted to give him the time he needs to develop."

With McGehee as a stopgap, the Marlins have no reason to rush Moran. There are also some other internal candidates, like Derek Dietrich and Donovan Solano, who can play third base.

Besides, Moran still needs more Minor League seasoning. With Greensboro last year, his hitting line was a promising .299/.354/.442. Moran added eight doubles, one triple, four homers and 23 RBIs.

After a long college season, plus being in the College World Series, Moran had a hectic 2013. Some in the Marlins organization felt he tired late in the year. In the Arizona Fall League, Moran experienced tougher competition and endured some struggles -- a .230 average with three doubles and 10 RBIs in 87 at-bats.

Even though Moran is not big league ready now, the 21-year-old will get a chance to impress the Miami coaching staff in a few weeks. The touted third-base prospect has an invitation to big league Spring Training.